1. Field of the Invention
This invention concerns an apparatus used during manufacture of air line panel filters or for any customer required panel filter glue applications, as well as to a process of manufacturing such filters.
2. Description of Related Art
One known apparatus for application of glue to filter elements is available from Graphischer Maschinenbau Nordhausen GmbH (“GMN”). During operation of this apparatus, glue is applied to a slick fiberglass belt moving at the same speed as a conveyor. As a filter element comes in contact with the belt, glue is transferred to the top of that element, with glue passing from the GMN glue gun at 400° F. The filter element is held between the belt and the conveyor for 28 inches while the glue cools. As the filter element exits the apparatus, the glue peels away and stays on top of the filter element.
Glue of the sort typically used in filter fabrication separates from the belt at approximately 180° F., when it is no longer tacky. The 28 inches of travel in the known GMN apparatus provides adequate time for the glue to harden so that it does not pull off. Cooling, however, is relatively slow; with a conveyor linear speed of about 15.5 feet per minute, production is limited to approximately 4-5 parts per minute. The length of the filter elements produced can also vary the number of parts processed per minute.